One recent study found an increase since 2008 in the hospitalization rate for stroke
associated with infective endocarditis and opioid use, while another compared outcomes
of infective endocarditis among patients who inject drugs versus those who do not.

Hospitalizations for strokes related to opioid use and infective endocarditis increased
significantly between 2008 and 2015, a study found.

From 1993 through 2015, there were 5,283 hospitalizations for stroke associated with
infective endocarditis and opioid use (mean patient age, 41.2 years; 34.2% women;
57.6% non-Hispanic white). The rate of such hospitalizations increased from 2.4 per
10 million U.S. residents in 1993 (95% CI, 0.5 to 4.3) to 18.8 per 10 million in 2015
(95% CI, 14.4 to 23.3). The rate did not significantly change between 1993 and 2008
(annual percentage change, 1.9%; 95% CI, −2.2% to 6.1%), but from 2008 to 2015,
it significantly increased (annual percentage change, 20.3%; 95% CI, 10.5% to 30.9%).
Non-Hispanic white patients in the Northeastern and Southern U.S. had the greatest
increases in the rate of hospitalization for stroke associated with infective endocarditis
and opioid use.

The authors noted limitations of the study, such as potential misclassification of
diagnoses in administrative claims data and a lack of access to granular clinical
information (e.g., cause, severity, and location of stroke). “These novel findings
indicate that increasing opioid abuse in the United States is not only causing more
social/occupational dysfunction, cardiac complications, and premature mortality but
may also be increasing the population burden of permanent functional disability as
a result of stroke,” they wrote.

In another study, researchers analyzed recent trends in hospitalizations for infective endocarditis and injection drug use and characterized patients' clinical outcomes and 30-day readmissions using the National
Readmissions Database from January 2010 to September 2015. They stratified patients
by injection drug use status and surgical versus medical management. Results were
published Feb. 5 by the Journal of the American College of Cardiology.

The survey-weighted sample contained 96,344 (77.8%) cases of infective endocarditis
not related to injection drug use and 27,432 (22.2%) cases related to injection drug
use. From 2010 through 2015, the proportion of infective endocarditis cases related
to injection drug use increased from 15.3% to 29.1% (P<0.001). Compared to nonrelated cases, cases related to injection drug use at
index hospitalization were associated with less mortality (6.8% vs. 9.6%; P<0.001) due to younger age, but similar risk of 30-day readmission (23.8% vs.
22.9%; P=0.077).

Limitations of the study include its retrospective nature, potential coding errors
within the National Readmissions Database, and a lack of detailed data, the study
authors said. Although patients with infective endocarditis related to injection drug
use seem to have lower mortality, their long-term mortality remains unknown, an accompanying
editorial noted. Future studies should assess the benefit of surgery in this population, particularly in the subgroup of those with persistent drug use, the editorialists
said.

“[I]ncreased focus on addiction treatment and social support following hospital
discharge is mandatory to reduce the risk of recurrent endocarditis,” they
wrote.

ACP Hospitalist provides news and information for hospitalists, covering the major issues in the field. All published material, which is covered by copyright, represents the views of the contributor and does not reflect the opinion of the American College of Physicians or any other institution unless clearly stated.